Verification of FLASH Implementations of the 3T Approximation for Plasma Hydrodynamics*

FLASH is a highly capable, fully modular, professionally managed Eulerian code with a wide user base. We are adding capabilities to FLASH to make it a n open code for the academic HEDP community. A key need is to provide the ability to model single-fluid plasmas as consisting of three coupled compone nts -- electrons, ions, and radiation in the diffusion approximation --- that can be described by 3 temperatures (3T). We discuss the challenges of im plementing the 3T approximation in an Eulerian code. We report the results of verification tests of the solvers we have implemented in FLASH for elect ron, ion, and radiation thermal diffusion, including flux limiting. We also report the results of a new hydrodynamics plus thermal conduction verifica tion test, and various 2T and 3T Su-Olson-type verification tests.